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<p>提供基本语法和方法的 C# 快速参考备忘单</p>
</div></header><div class="menu-tocs"><div class="menu-btn"><svg aria-hidden="true" fill="currentColor" height="1em" width="1em" viewBox="0 0 16 16" version="1.1" data-view-component="true">
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</svg></div><div class="menu-modal"><a aria-hidden="true" class="leve2 tocs-link" data-num="2" href="#入门">入门</a><a aria-hidden="true" class="leve3 tocs-link" data-num="3" href="#hellocs">Hello.cs</a><a aria-hidden="true" class="leve3 tocs-link" data-num="3" href="#变量">变量</a><a aria-hidden="true" class="leve3 tocs-link" data-num="3" href="#原始数据类型">原始数据类型</a><a aria-hidden="true" class="leve3 tocs-link" data-num="3" href="#注释">注释</a><a aria-hidden="true" class="leve3 tocs-link" data-num="3" href="#字符串">字符串</a><a aria-hidden="true" class="leve3 tocs-link" data-num="3" href="#用户输入">用户输入</a><a aria-hidden="true" class="leve3 tocs-link" data-num="3" href="#条件判断">条件判断</a><a aria-hidden="true" class="leve3 tocs-link" data-num="3" href="#数组">数组</a><a aria-hidden="true" class="leve3 tocs-link" data-num="3" href="#循环">循环</a><a aria-hidden="true" class="leve2 tocs-link" data-num="2" href="#c-字符串">C# 字符串</a><a aria-hidden="true" class="leve3 tocs-link" data-num="3" href="#字符串连接">字符串连接</a><a aria-hidden="true" class="leve3 tocs-link" data-num="3" href="#字符串插值">字符串插值</a><a aria-hidden="true" class="leve3 tocs-link" data-num="3" href="#字符串成员">字符串成员</a><a aria-hidden="true" class="leve3 tocs-link" data-num="3" href="#逐字字符串">逐字字符串</a><a aria-hidden="true" class="leve3 tocs-link" data-num="3" href="#成员示例">成员示例</a><a aria-hidden="true" class="leve3 tocs-link" data-num="3" href="#频繁字符串拼接">频繁字符串拼接</a><a aria-hidden="true" class="leve3 tocs-link" data-num="3" href="#原始字符串文本">原始字符串文本</a><a aria-hidden="true" class="leve2 tocs-link" data-num="2" href="#杂项">杂项</a><a aria-hidden="true" class="leve3 tocs-link" data-num="3" href="#常用-net-概念">常用 .NET 概念</a></div></div><div class="h1wrap-body"><div class="wrap h2body-exist"><div class="wrap-header h2wrap"><h2 id="入门"><a aria-hidden="true" tabindex="-1" href="#入门"><span class="icon icon-link"></span></a>入门</h2><div class="wrap-body">
</div></div><div class="h2wrap-body"><div class="wrap h3body-not-exist"><div class="wrap-header h3wrap"><h3 id="hellocs"><a aria-hidden="true" tabindex="-1" href="#hellocs"><span class="icon icon-link"></span></a>Hello.cs</h3><div class="wrap-body">
<pre class="language-cs"><code class="language-cs code-highlight"><span class="code-line"><span class="token keyword">class</span> <span class="token class-name">Hello</span> <span class="token punctuation">{</span>
</span><span class="code-line">  <span class="token comment">// main method</span>
</span><span class="code-line">  <span class="token keyword">static</span> <span class="token return-type class-name"><span class="token keyword">void</span></span> <span class="token function">Main</span><span class="token punctuation">(</span><span class="token class-name"><span class="token keyword">string</span><span class="token punctuation">[</span><span class="token punctuation">]</span></span> args<span class="token punctuation">)</span>
</span><span class="code-line">  <span class="token punctuation">{</span>
</span><span class="code-line">    <span class="token comment">// 输出: Hello, world!</span>
</span><span class="code-line">    Console<span class="token punctuation">.</span><span class="token function">WriteLine</span><span class="token punctuation">(</span><span class="token string">"Hello, world!"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
</span><span class="code-line">  <span class="token punctuation">}</span>
</span><span class="code-line"><span class="token punctuation">}</span>
</span></code></pre>
<p>编译运行（确保在项目目录下）</p>
<pre class="language-shell"><code class="language-shell code-highlight"><span class="code-line">$ dotnet run
</span><span class="code-line">Hello, world<span class="token operator">!</span>
</span></code></pre>
</div></div></div><div class="wrap h3body-not-exist"><div class="wrap-header h3wrap"><h3 id="变量"><a aria-hidden="true" tabindex="-1" href="#变量"><span class="icon icon-link"></span></a>变量</h3><div class="wrap-body">
<pre class="language-cs"><code class="language-cs code-highlight"><span class="code-line"><span class="token class-name"><span class="token keyword">int</span></span> intNum <span class="token operator">=</span> <span class="token number">9</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token class-name"><span class="token keyword">long</span></span> longNum <span class="token operator">=</span> <span class="token number">9999999</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token class-name"><span class="token keyword">float</span></span> floatNum <span class="token operator">=</span> <span class="token number">9.99F</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token class-name"><span class="token keyword">double</span></span> doubleNum <span class="token operator">=</span> <span class="token number">99.999</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token class-name"><span class="token keyword">decimal</span></span> decimalNum <span class="token operator">=</span> <span class="token number">99.9999M</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token class-name"><span class="token keyword">char</span></span> letter <span class="token operator">=</span> <span class="token char">'D'</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token class-name"><span class="token keyword">bool</span></span> @<span class="token keyword">bool</span> <span class="token operator">=</span> <span class="token boolean">true</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token class-name"><span class="token keyword">string</span></span> site <span class="token operator">=</span> <span class="token string">"jaywcjlove.github.io"</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token class-name"><span class="token keyword">var</span></span> num <span class="token operator">=</span> <span class="token number">999</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token class-name"><span class="token keyword">var</span></span> str <span class="token operator">=</span> <span class="token string">"999"</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token class-name"><span class="token keyword">var</span></span> bo <span class="token operator">=</span> <span class="token boolean">false</span><span class="token punctuation">;</span>
</span></code></pre>
</div></div></div><div class="wrap h3body-not-exist"><div class="wrap-header h3wrap"><h3 id="原始数据类型"><a aria-hidden="true" tabindex="-1" href="#原始数据类型"><span class="icon icon-link"></span></a>原始数据类型</h3><div class="wrap-body">


















































<table class="show-header"><thead><tr><th align="left">数据类型</th><th>尺寸</th><th>范围</th></tr></thead><tbody><tr><td align="left"><code>int</code></td><td>4 bytes</td><td>-2^31^ ^to^ 2^31^-1</td></tr><tr><td align="left"><code>long</code></td><td>8 bytes</td><td>-2^63^ ^to^ 2^63^-1</td></tr><tr><td align="left"><code>float</code></td><td>4 bytes</td><td>6 ^to^ 7 decimal digits</td></tr><tr><td align="left"><code>double</code></td><td>8 bytes</td><td>15 decimal digits</td></tr><tr><td align="left"><code>decimal</code></td><td>16 bytes</td><td>28 ^to^ 29 decimal digits</td></tr><tr><td align="left"><code>char</code></td><td>2 bytes</td><td>0 ^to^ 65535</td></tr><tr><td align="left"><code>bool</code></td><td>1 bit</td><td>true / false</td></tr><tr><td align="left"><code>string</code></td><td>2 bytes per char</td><td><em>N/A</em></td></tr></tbody></table>
<!--rehype:className=show-header-->
</div></div></div><div class="wrap h3body-not-exist"><div class="wrap-header h3wrap"><h3 id="注释"><a aria-hidden="true" tabindex="-1" href="#注释"><span class="icon icon-link"></span></a>注释</h3><div class="wrap-body">
<pre class="language-cs"><code class="language-cs code-highlight"><span class="code-line"><span class="token comment">// 单行注释</span>
</span><span class="code-line"><span class="token comment">/* 多行
</span></span><span class="code-line"><span class="token comment">   注释 */</span>
</span><span class="code-line"><span class="token comment">// TODO：向 Visual Studio 中的任务列表添加注释</span>
</span><span class="code-line"><span class="token doc-comment comment">/// 用于文档的单行注释</span>
</span><span class="code-line"><span class="token comment">/** 多行 注释 
</span></span><span class="code-line"><span class="token comment">    用于文档 **/</span>
</span></code></pre>
</div></div></div><div class="wrap h3body-not-exist"><div class="wrap-header h3wrap"><h3 id="字符串"><a aria-hidden="true" tabindex="-1" href="#字符串"><span class="icon icon-link"></span></a>字符串</h3><div class="wrap-body">
<pre class="language-cs"><code class="language-cs code-highlight"><span class="code-line"><span class="token class-name"><span class="token keyword">string</span></span> first <span class="token operator">=</span> <span class="token string">"John"</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token class-name"><span class="token keyword">string</span></span> last <span class="token operator">=</span> <span class="token string">"Doe"</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token comment">// 字符串连接</span>
</span><span class="code-line"><span class="token class-name"><span class="token keyword">string</span></span> name <span class="token operator">=</span> first <span class="token operator">+</span> <span class="token string">" "</span> <span class="token operator">+</span> last<span class="token punctuation">;</span>
</span><span class="code-line">Console<span class="token punctuation">.</span><span class="token function">WriteLine</span><span class="token punctuation">(</span>name<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">// => John Doe</span>
</span></code></pre>
<p>查看: <a href="#c-%E5%AD%97%E7%AC%A6%E4%B8%B2">C#字符串</a></p>
</div></div></div><div class="wrap h3body-not-exist"><div class="wrap-header h3wrap"><h3 id="用户输入"><a aria-hidden="true" tabindex="-1" href="#用户输入"><span class="icon icon-link"></span></a>用户输入</h3><div class="wrap-body">
<pre class="language-cs"><code class="language-cs code-highlight"><span class="code-line line-number" line="1">Console<span class="token punctuation">.</span><span class="token function">WriteLine</span><span class="token punctuation">(</span><span class="token string">"Enter number:"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
</span><span class="code-line line-number" line="2"><span class="token keyword">if</span><span class="token punctuation">(</span><span class="token keyword">int</span><span class="token punctuation">.</span><span class="token function">TryParse</span><span class="token punctuation">(</span>Console<span class="token punctuation">.</span><span class="token function">ReadLine</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span><span class="token keyword">out</span> <span class="token class-name"><span class="token keyword">int</span></span> input<span class="token punctuation">)</span><span class="token punctuation">)</span>
</span><span class="code-line line-number" line="3"><span class="token punctuation">{</span>
</span><span class="code-line line-number" line="4">  <span class="token comment">// 输入验证</span>
</span><span class="code-line line-number" line="5">  Console<span class="token punctuation">.</span><span class="token function">WriteLine</span><span class="token punctuation">(</span><span class="token interpolation-string"><span class="token string">$"You entered </span><span class="token interpolation"><span class="token punctuation">{</span><span class="token expression language-csharp">input</span><span class="token punctuation">}</span></span><span class="token string">"</span></span><span class="token punctuation">)</span><span class="token punctuation">;</span>
</span><span class="code-line line-number" line="6"><span class="token punctuation">}</span>
</span></code></pre>
</div></div></div><div class="wrap h3body-not-exist"><div class="wrap-header h3wrap"><h3 id="条件判断"><a aria-hidden="true" tabindex="-1" href="#条件判断"><span class="icon icon-link"></span></a>条件判断</h3><div class="wrap-body">
<pre class="language-cs"><code class="language-cs code-highlight"><span class="code-line"><span class="token class-name"><span class="token keyword">int</span></span> j <span class="token operator">=</span> <span class="token number">10</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token keyword">if</span> <span class="token punctuation">(</span>j <span class="token operator">==</span> <span class="token number">10</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
</span><span class="code-line">  Console<span class="token punctuation">.</span><span class="token function">WriteLine</span><span class="token punctuation">(</span><span class="token string">"I get printed"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token keyword">if</span> <span class="token punctuation">(</span>j <span class="token operator">></span> <span class="token number">10</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
</span><span class="code-line">  Console<span class="token punctuation">.</span><span class="token function">WriteLine</span><span class="token punctuation">(</span><span class="token string">"I don't"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token punctuation">{</span>
</span><span class="code-line">  Console<span class="token punctuation">.</span><span class="token function">WriteLine</span><span class="token punctuation">(</span><span class="token string">"I also don't"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token punctuation">}</span>
</span></code></pre>
</div></div></div><div class="wrap h3body-not-exist"><div class="wrap-header h3wrap"><h3 id="数组"><a aria-hidden="true" tabindex="-1" href="#数组"><span class="icon icon-link"></span></a>数组</h3><div class="wrap-body">
<pre class="language-cs"><code class="language-cs code-highlight"><span class="code-line"><span class="token class-name"><span class="token keyword">char</span><span class="token punctuation">[</span><span class="token punctuation">]</span></span> chars <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token constructor-invocation class-name"><span class="token keyword">char</span></span><span class="token punctuation">[</span><span class="token number">10</span><span class="token punctuation">]</span><span class="token punctuation">;</span>
</span><span class="code-line">chars<span class="token punctuation">[</span><span class="token number">0</span><span class="token punctuation">]</span> <span class="token operator">=</span> <span class="token char">'a'</span><span class="token punctuation">;</span>
</span><span class="code-line">chars<span class="token punctuation">[</span><span class="token number">1</span><span class="token punctuation">]</span> <span class="token operator">=</span> <span class="token char">'b'</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token class-name"><span class="token keyword">string</span><span class="token punctuation">[</span><span class="token punctuation">]</span></span> letters <span class="token operator">=</span> <span class="token punctuation">{</span><span class="token string">"A"</span><span class="token punctuation">,</span> <span class="token string">"B"</span><span class="token punctuation">,</span> <span class="token string">"C"</span><span class="token punctuation">}</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token class-name"><span class="token keyword">int</span><span class="token punctuation">[</span><span class="token punctuation">]</span></span> mylist <span class="token operator">=</span> <span class="token punctuation">{</span><span class="token number">100</span><span class="token punctuation">,</span> <span class="token number">200</span><span class="token punctuation">}</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token class-name"><span class="token keyword">bool</span><span class="token punctuation">[</span><span class="token punctuation">]</span></span> answers <span class="token operator">=</span> <span class="token punctuation">{</span><span class="token boolean">true</span><span class="token punctuation">,</span> <span class="token boolean">false</span><span class="token punctuation">}</span><span class="token punctuation">;</span>
</span></code></pre>
</div></div></div><div class="wrap h3body-not-exist"><div class="wrap-header h3wrap"><h3 id="循环"><a aria-hidden="true" tabindex="-1" href="#循环"><span class="icon icon-link"></span></a>循环</h3><div class="wrap-body">
<pre class="language-cs"><code class="language-cs code-highlight"><span class="code-line"><span class="token class-name"><span class="token keyword">int</span><span class="token punctuation">[</span><span class="token punctuation">]</span></span> numbers <span class="token operator">=</span> <span class="token punctuation">{</span><span class="token number">1</span><span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">,</span> <span class="token number">4</span><span class="token punctuation">,</span> <span class="token number">5</span><span class="token punctuation">}</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token keyword">for</span><span class="token punctuation">(</span><span class="token class-name"><span class="token keyword">int</span></span> i <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span> i <span class="token operator">&#x3C;</span> numbers<span class="token punctuation">.</span>Length<span class="token punctuation">;</span> i<span class="token operator">++</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
</span><span class="code-line">  Console<span class="token punctuation">.</span><span class="token function">WriteLine</span><span class="token punctuation">(</span>numbers<span class="token punctuation">[</span>i<span class="token punctuation">]</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token punctuation">}</span>
</span></code></pre>
<hr>
<pre class="language-cs"><code class="language-cs code-highlight"><span class="code-line"><span class="token keyword">foreach</span><span class="token punctuation">(</span><span class="token class-name"><span class="token keyword">int</span></span> num <span class="token keyword">in</span> numbers<span class="token punctuation">)</span> <span class="token punctuation">{</span>
</span><span class="code-line">  Console<span class="token punctuation">.</span><span class="token function">WriteLine</span><span class="token punctuation">(</span>num<span class="token punctuation">)</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token punctuation">}</span>
</span></code></pre>
</div></div></div></div></div><div class="wrap h2body-exist"><div class="wrap-header h2wrap"><h2 id="c-字符串"><a aria-hidden="true" tabindex="-1" href="#c-字符串"><span class="icon icon-link"></span></a>C# 字符串</h2><div class="wrap-body">
</div></div><div class="h2wrap-body"><div class="wrap h3body-not-exist"><div class="wrap-header h3wrap"><h3 id="字符串连接"><a aria-hidden="true" tabindex="-1" href="#字符串连接"><span class="icon icon-link"></span></a>字符串连接</h3><div class="wrap-body">
<pre class="language-cs"><code class="language-cs code-highlight"><span class="code-line"><span class="token class-name"><span class="token keyword">string</span></span> first <span class="token operator">=</span> <span class="token string">"John"</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token class-name"><span class="token keyword">string</span></span> last <span class="token operator">=</span> <span class="token string">"Doe"</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token class-name"><span class="token keyword">string</span></span> name <span class="token operator">=</span> first <span class="token operator">+</span> <span class="token string">" "</span> <span class="token operator">+</span> last<span class="token punctuation">;</span>
</span><span class="code-line">Console<span class="token punctuation">.</span><span class="token function">WriteLine</span><span class="token punctuation">(</span>name<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">// => John Doe</span>
</span></code></pre>
</div></div></div><div class="wrap h3body-not-exist"><div class="wrap-header h3wrap"><h3 id="字符串插值"><a aria-hidden="true" tabindex="-1" href="#字符串插值"><span class="icon icon-link"></span></a>字符串插值</h3><div class="wrap-body">
<pre class="language-cs"><code class="language-cs code-highlight"><span class="code-line"><span class="token class-name"><span class="token keyword">string</span></span> first <span class="token operator">=</span> <span class="token string">"John"</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token class-name"><span class="token keyword">string</span></span> last <span class="token operator">=</span> <span class="token string">"Doe"</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token class-name"><span class="token keyword">string</span></span> name <span class="token operator">=</span> <span class="token interpolation-string"><span class="token string">$"</span><span class="token interpolation"><span class="token punctuation">{</span><span class="token expression language-csharp">first</span><span class="token punctuation">}</span></span><span class="token string"> </span><span class="token interpolation"><span class="token punctuation">{</span><span class="token expression language-csharp">last</span><span class="token punctuation">}</span></span><span class="token string">"</span></span><span class="token punctuation">;</span>
</span><span class="code-line">Console<span class="token punctuation">.</span><span class="token function">WriteLine</span><span class="token punctuation">(</span>name<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">// => John Doe</span>
</span></code></pre>
</div></div></div><div class="wrap h3body-not-exist row-span-2"><div class="wrap-header h3wrap"><h3 id="字符串成员"><a aria-hidden="true" tabindex="-1" href="#字符串成员"><span class="icon icon-link"></span></a>字符串成员</h3><div class="wrap-body">
<!--rehype:wrap-class=row-span-2-->





































<table class="show-header"><thead><tr><th align="left">成员</th><th>说明</th></tr></thead><tbody><tr><td align="left"><code>Length</code></td><td>返回字符串长度的属性</td></tr><tr><td align="left"><code>Compare()</code></td><td>比较两个字符串的静态方法</td></tr><tr><td align="left"><code>Contains()</code></td><td>确定字符串是否包含特定的子字符串</td></tr><tr><td align="left"><code>Equals()</code></td><td>确定两个字符串是否具有相同的字符数据</td></tr><tr><td align="left"><code>Format()</code></td><td>通过 {0} 表示法和使用其他原语格式化字符串</td></tr><tr><td align="left"><code>Trim()</code></td><td>从尾随和前导字符中删除特定字符的所有实例。 默认删除前导和尾随空格</td></tr><tr><td align="left"><code>Split()</code></td><td>删除提供的字符并从两侧的剩余字符中创建一个数组</td></tr></tbody></table>
<!--rehype:className=show-header-->
</div></div></div><div class="wrap h3body-not-exist"><div class="wrap-header h3wrap"><h3 id="逐字字符串"><a aria-hidden="true" tabindex="-1" href="#逐字字符串"><span class="icon icon-link"></span></a>逐字字符串</h3><div class="wrap-body">
<pre class="wrap-text"><code class="language-cs code-highlight"><span class="code-line line-number" line="1"><span class="token class-name"><span class="token keyword">string</span></span> longString <span class="token operator">=</span> <span class="token string">@"I can type any characters in here !#@$%^&#x26;*()__+ '' \n \t except double quotes and I will be taken literally. I even work with multiple lines."</span><span class="token punctuation">;</span>
</span></code></pre>
<!--rehype:className=wrap-text-->
</div></div></div><div class="wrap h3body-not-exist"><div class="wrap-header h3wrap"><h3 id="成员示例"><a aria-hidden="true" tabindex="-1" href="#成员示例"><span class="icon icon-link"></span></a>成员示例</h3><div class="wrap-body">
<pre class="language-cs"><code class="language-cs code-highlight"><span class="code-line"><span class="token comment">// 使用 System.String 的属性</span>
</span><span class="code-line"><span class="token class-name"><span class="token keyword">string</span></span> lengthOfString <span class="token operator">=</span> <span class="token string">"How long?"</span><span class="token punctuation">;</span>
</span><span class="code-line">lengthOfString<span class="token punctuation">.</span>Length           <span class="token comment">// => 9</span>
</span><span class="code-line"><span class="token comment">// 使用 System.String 的方法</span>
</span><span class="code-line">lengthOfString<span class="token punctuation">.</span><span class="token function">Contains</span><span class="token punctuation">(</span><span class="token string">"How"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">// => true</span>
</span></code></pre>
</div></div></div><div class="wrap h3body-not-exist"><div class="wrap-header h3wrap"><h3 id="频繁字符串拼接"><a aria-hidden="true" tabindex="-1" href="#频繁字符串拼接"><span class="icon icon-link"></span></a>频繁字符串拼接</h3><div class="wrap-body">
<pre class="language-cs"><code class="language-cs code-highlight"><span class="code-line"><span class="token class-name"><span class="token keyword">var</span></span> sb <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token constructor-invocation class-name">StringBuilder</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token keyword">for</span> <span class="token punctuation">(</span><span class="token class-name"><span class="token keyword">int</span></span> i <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span> i <span class="token operator">&#x3C;</span> <span class="token number">100</span><span class="token punctuation">;</span> i<span class="token operator">++</span><span class="token punctuation">)</span>
</span><span class="code-line"><span class="token punctuation">{</span>
</span><span class="code-line">    sb<span class="token punctuation">.</span><span class="token function">Append</span><span class="token punctuation">(</span>i<span class="token punctuation">.</span><span class="token function">ToString</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token punctuation">}</span>
</span><span class="code-line">Console<span class="token punctuation">.</span><span class="token function">WriteLine</span><span class="token punctuation">(</span>sb<span class="token punctuation">.</span><span class="token function">ToString</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
</span><span class="code-line"><span class="token comment">// => 123456789....</span>
</span></code></pre>
<p>对于频繁拼接字符串的场景（如：成百上千次循环），使用 <code>System.Text.StringBuilder</code> 提升性能</p>
</div></div></div><div class="wrap h3body-not-exist col-span-2"><div class="wrap-header h3wrap"><h3 id="原始字符串文本"><a aria-hidden="true" tabindex="-1" href="#原始字符串文本"><span class="icon icon-link"></span></a>原始字符串文本</h3><div class="wrap-body">
<!--rehype:wrap-class=col-span-2-->
<pre class="language-cs"><code class="language-cs code-highlight"><span class="code-line"><span class="token comment">// C#11 语法, 至少3个双引号(""")开头和结尾，内容可以输入任何原始字符</span>
</span><span class="code-line"><span class="token comment">// 单行: 左引号，右引号，内容 三者同行</span>
</span><span class="code-line"><span class="token class-name"><span class="token keyword">string</span></span> singleLine <span class="token operator">=</span> <span class="token string">""</span>"Content begin <span class="token string">"Hello World!"</span> end<span class="token punctuation">.</span><span class="token string">""</span>"<span class="token punctuation">;</span>
</span><span class="code-line">
</span><span class="code-line"><span class="token comment">// 多行：左引号，右引号各一行，内容需与右引号缩进对齐</span>
</span><span class="code-line"><span class="token class-name"><span class="token keyword">string</span></span> multiLine <span class="token operator">=</span> <span class="token string">""</span>"
</span><span class="code-line">    Content begin <span class="token string">"Hello World!"</span> <span class="token operator">/</span>\n<span class="token operator">&#x3C;</span><span class="token operator">></span><span class="token string">""</span> end<span class="token punctuation">.</span>
</span><span class="code-line">    <span class="token string">""</span>"<span class="token punctuation">;</span>
</span><span class="code-line">Console<span class="token punctuation">.</span><span class="token function">WriteLine</span><span class="token punctuation">(</span>multiLine<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">// => Content begin "Hello World!" /\n&#x3C;>"" end.</span>
</span></code></pre>
</div></div></div></div></div><div class="wrap h2body-exist"><div class="wrap-header h2wrap"><h2 id="杂项"><a aria-hidden="true" tabindex="-1" href="#杂项"><span class="icon icon-link"></span></a>杂项</h2><div class="wrap-body">
</div></div><div class="h2wrap-body"><div class="wrap h3body-not-exist col-span-3"><div class="wrap-header h3wrap"><h3 id="常用-net-概念"><a aria-hidden="true" tabindex="-1" href="#常用-net-概念"><span class="icon icon-link"></span></a>常用 .NET 概念</h3><div class="wrap-body">
<!--rehype:wrap-class=col-span-3-->






























<table class="show-header"><thead><tr><th align="left">概念</th><th>中文名</th><th>定义</th></tr></thead><tbody><tr><td align="left">Runtime</td><td>运行时</td><td>执行给定的已编译代码单元所需的服务集合</td></tr><tr><td align="left">Common Language Runtime (CLR)</td><td>通用语言运行库</td><td>主要定位、加载和托管 .NET 对象。<br>CLR 还处理内存管理、应用程序托管、线程协调、执行安全检查和其他低级细节</td></tr><tr><td align="left">Managed code</td><td>托管代码</td><td>在 <code>.NET</code> 运行时编译和运行的代码。 C#/F#/VB 就是例子</td></tr><tr><td align="left">Unmanaged code</td><td>非托管代码</td><td>直接编译为机器代码且不能由 .NET 运行时直接托管的代码。<br>不包含空闲内存管理、垃圾收集等。从 C/C++ 创建的 DLL 就是示例</td></tr></tbody></table>
<!--rehype:className=show-header-->
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